Biological systems in general – and nervous systems in particular – are strikingly complex. For centuries, scientists have made progress by isolating and characterizing individual units of these systems. However, the units are not enough to explain the system; we need a language in which to encode the intricate patterns of unit-to-unit interactions. Dani Bassett will discuss how network science provides this type of language, embracing greater complexity while distilling the simple rules of biological architecture and function.